body{
    margin: 0;
    padding: 0;
}
ul{
    list-style: none;
    margin: 0;
    padding: 0;
}
header{
    height: 50px;
    background-color: rgb(65, 83, 122);
}
nav{
    width: 1200px;
    margin: 0 auto;
    height: 100%;
    /* background-color: rgb(221, 80, 80); */
}

.item{
    float: left;
    background-color: rgb(65, 83, 122);
    position: relative;
}
.item:hover .sub-menu{
    display: block;
}
.item a{
    display: block;
    text-decoration: none;
    color: white;
    /* background-color: rgb(248, 150, 150); */
    height: 50px;
    line-height: 50px;
    padding:0 20px;
    border-left: 2px solid transparent;
    

}
.item a:hover{
    border-color: tomato;
}
.sub-menu{
    display: none;
    position: absolute;
    background-color: rgb(65, 83, 122);
    top:50px;
}
.sub-menu a{
    width: 100px;
}
